Wet oxidation is a known technology and is practiced commercially. See, for example, Zimmermann U.S. Pat. Nos. 2,665,249, 2,824,058, and 2,903,425, and Barton et al U.S. Pat. No. 2,944,396. Systems for producing useful energy with wet oxidation systems have been patented and placed in commercial use.
FIG. 1 is a flow sheet of a prior art example of a wet oxidation system as practiced commercially to the present time. Generally it is stressed that the fuel value in such a system is a "waste" dispersed in water. The emphasis has been on the treatment of waste streams and energy production is secondary or incidental. This is proper for waste treatment where the primary purpose of the wet oxidation unit is treatment of the waste and elimination of pollution. However there is a class of combustible materials, for example, solid wastes or refuse, low grade fuels or fuels which present problems in conventional combustion, for example, fuels having high moisture content, high ash content or high sulfur content, to which wet oxidation can be advantageously applied and for which a modified and improved wet oxidation system and apparatus, optimized for energy recovery can be used. The present invention arises from the need for such a system.